Port server II Modem8em

Hi, I have a Digi Port server II16 unit connected to a set of Digi Modem 8em which comunicate a group of compatible serial devices. I need to develop a software aplication to manage this devices. I would like to know from you what are the LAN communication protocols used by the Digi Port server II16 and the Digi Modem 8em, i need to know how the serial data from the modems 8em came to my computer, thanks for the help you could give me.

It sounds like you need the “RealPort” software that configures TTY devices on your host system in order to communicate with the serial ports.

This driver is available for download from Digi’s web-site:


Thank you
I have a simple serial device attached to the modem 8em but i don’t know his instruction set, i would like to know if it is possible to capture its data packets with a network analyzer tool (like a sniffer) to develop a software to manage this device

I doubt a network sniff will be very useful.

Besides, the Modem/EM product does not have serial ports, only modems. What sort of “serial” device are you planning on using with these ports?

What is the reason you cannot use the Digi RealPort driver?

Ok, the serial devices are monitoring units who establishes communication with the modems, right now they work fine together, i would like to develop a new software to manage this monitoring units, maybe with a network sniffer it would be possible to know its instruction set.

Here are the links to the Administration Guide and the Command Reference for the Portserver II:


That’s the closest thing we have to an instruction set for this product.